TC1767 Datasheet, PDF (106/126 Pages) Infineon Technologies AG – 32-Bit Single-Chip Microcontroller

5.3.3 Power Sequencing
TC1767
Electrical Parameters
V
5V
3.3V
1.5V
V_DDP
+-5%
+-5%
0.5V
0.5V
+-5%
V_AREF
-12%
-12%
0.5V
t
PORST
power
down
power
fail
t
Power-Up 8.vsd
Figure 24 5 V / 3.3 V / 1.5 V Power-Up/Down Sequence
The following list of rules applies to the power-up/down sequence:
• All ground pins V_SS must be externally connected to one single star point in the
system. Regarding the DC current component, all ground pins are internally directly
connected.
1. At any moment,
each power supply must be higher than any lower_power_supply - 0.5 V, or:
V_DD5 > V_DD3.3 - 0.5 V; V_DD5 > V_DD1.5 - 0.5 V;V_DD3.3 > V_DD1.5 - 0.5 V, see Figure 24.
2. During power-up and power-down, the voltage difference between the power supply
pins of the same voltage (3.3 V, 1.5 V, and 5 V) with different names (for example
V_DDP, V_DDFL3 ...), that are internaly connected via diodes must be lower than 100 mV.
On the other hand, all power supply pins with the same name (for example all V_DDP
), are internaly directly connected. It is recommended that the power pins of the same
voltage are driven by a single power supply.
Data Sheet
102
V1.3, 2009-09